In the prior art, various methods for determining parameters of a bottomhole and a near-bottomhole zone are known. In particular, the U.S. Pat. No. 4,799,157 describes a method for determining permeability and skin factor of two layers of a single reservoir. The method consists in performing two consecutive drill-hole hydrodynamic tests by means of creating a drawdown at the bottomhole with swapping of the production logging tool and subsequent interpretation of production rate and pressure data.
U.S. Pat. No. 5,337,821 shows a method for calculating formation fluid transmissibility as well as a method and metering apparatus for measuring production rates, open flow potential of the well, and for determining the dependency of near-bottomhole formation damage versus production rate. Measurements are conducted after deployment of the tool to a preset depth and isolation of intervals with the use of inflatable elastomer packers.
U.S. Pat. No. 7,675,287 describes a method for estimation of skin factor of a subsurface reservoir inside a wellbore by means of deployment of a measuring apparatus to a preset depth and measuring nuclear magnetic resonance of the formation at multiple depths.
US Patent Application No. 2011/0087471 proposes to establish a functional relationship between properties of the reservoir, characteristics of the near-bottomhole zone/completion of the well, and the measurable characteristics of the well. Confirmed values of reservoir properties, for example, permeability; characteristics of the near-wellbore zone/completion, for example, skin factor, are determined provided that the functional relationship is established.
The common drawback of the patents and patent applications is that all of them require special equipment or special downhole operations for determining properties of the bottomhole and the near-bottomhole zone. The distinction of the present invention is that information usually available in the course of well tests or well operation is used for determining properties of the bottomhole and the near-bottomhole zone. In other words, no non-standard equipment or additional operations are required for determining the parameters.